1. Field of Invention
The present invention relates to a manufacturing method of a heat dissipation assembly.
2. Description of Related Art
In operation, electric elements of a computer, such as central processing units (CPU), south bridge chips, north bridge chips, display chips, etc., would generate heat. The chips consume less and less electricity along with the progress in semiconductor manufacturing process. Therefore, fan modules may not be necessary anymore as heat dissipation modules, which saves case space and to reduce operation noise. Instead, heat spreading materials or assemblies that have heat pipes and metal boards are utilized as heat dissipation modules.
The heat spreading material may be graphite material, copper foil, aluminum foil, or composite material. Although the heat spreading material requires less space, the heat spreading material has disadvantages of high cost and low heat dissipation capacity. In the manufacture of the assembly having the heat pipe and the metal board, soldering process is usually applied to fix the heat pipe on the metal board. The metal board needs to be in advance processed by CNC cutting process and stamping process to form a concave portion for accommodating the heat pipe. Next, the heat pipe can be placed in the concave portion of the metal board, and the heat pipe and the metal board may be soldered.
When an end of the heat pipe is located at a high temperature position and another end of the heat pipe at a low temperature position, working liquid fluid adsorbed by capillary bodies at the high temperature position would start to evaporate. The evaporated gas gathers in the space of the pipe and becomes gaseous fluid flowing to the low temperature position of the heat pipe due to pressure. When the gaseous fluid flows to the low temperature position, the gaseous fluid starts to condense back into liquid fluid, and the liquid fluid is adsorbed by capillary bodies at the low temperature position. Finally, the liquid fluid returns to the high temperature position from the low temperature position by the capillary phenomena of the capillary bodies. The working fluid continuously circulates to transfer heat by utilizing gas-liquid phase transformation.
There are some disadvantages in conventional art for manufacturing the assembly having the heat pipe and the metal board. For example, it is required to use at least three processes (including stamping, CNC cutting, and soldering) to assemble the heat pipe and the metal board, so that the labor cost and the process cost are increased. Moreover, when the multiple processes are involved, not only the entire yield rate decreases, but the CNC cutting process and the soldering process would reduce the mechanical strength of the heat pipe and the metal board.